The invention relates to an air intake channel system for internal combustion engines, particularly for V engines.
From DE 197 56 332, an air intake channel system is known where the length of several air intake channels each of which is connectable to a cylinder of an internal combustion engine is adapted to be continuously varied. To this end, the spirally configured intake channels are arranged next to each other. Each spiral air intake channel comprises an air inlet opening connected to a central inner region of the air intake system. Through said air inlet opening, air enters into the spiral channel and is led to the respective cylinder after it has flown through the spiral channel. Within the central region, a tubular channel member is arranged which forms the inner wall of the spiral channel and comprises the air inlet opening. The tubular channel member is pivotably arranged so that the position of the air entrance opening can be varied. By pivoting the tubular channel member, the length of the air intake channel, i.e., the distance between the air entrance opening and the air exit opening to be flown through by the air, can thus be continuously varied.
The individual channel members forming the intake channels are arranged adjacent to each other or stacked upon each other, the configured air intake channels being alternately connected with the one or the other row of the cylinders of the V engine. For pivoting the inner pivotable channel members, they are connected to a pivot axis. Thus, each air intake channel is formed substantially by a stationary channel member and a pivotable channel member. The tubular pivotable channel member is supported in a recess of the stationary channel member. Since the cross-section of the individual air intake channels has to be relatively large to provide a sufficient amount of air, such air intake channel systems with variable lengths of the air intake channels are built very large, particularly in six or eight cylinder engines.
It is the object of the invention to provide an air intake channel system with a variable length of the air intake channels the required building space of which is reduced.
In the air intake channel system according to the invention, two adjacent air intake channels, respectively, are combined. Thereby, the building space of the air intake channel system can be halved approximately. To be able to combine two adjacent air intake channels, according to the invention, a common pivotable channel member is provided for these two air intake channels. According to the invention, the channel member has two air inlet openings that are connected to one of the two air intake channels, respectively. In case of an air intake channel system assembled, in principle, in the same manner as in DE 197 56 332, with several pivotable inner channel members arranged adjacent to each other and surrounded by outer channel members so that annular air intake channels are created, it has been noted that the variability of the length of the intake channel does not have to be as great as with such air intake channel systems. Therefore, it is possible to arrange two adjacent air intake channels preferably in one plane. For an air intake channel system having, in principle, the same structure as previously described, this means that the channel that is annular in this manner is substantially halved so that, per intake channel, half of a ring can be substantially used as variable length of the intake channel.
Preferably, the two intake channels partly surround the inner pivotable channel member, respectively.
In an eight cylinder engine, for example, four air intake channel units assembled according to the invention are provided. They are preferably actuated via a single common shaft for pivoting the pivotable channel members. Thus, it is possible by providing, according to the invention, air intake channel units with respectively two air intake channels to provide only one drive shaft. This considerably simplifies the construction of the air intake channel system in comparison with prior art where two drive shafts have to be provided. Particularly, the manufacturing costs are reduced thereby as well, since both less components are required and the assembly of the individual components can be formed simpler. Since less components are required, a smaller addition of tolerances takes place so that a smaller overall tolerance can be achieved. By pivoting the common drive shaft, the intake length of the air intake channels is simultaneously changed for all the cylinders. Pivoting the common pivotable channel member particularly effects the simultaneous variation of the intake length of the air intake channel of the two air intake channels forming the air intake channel unit.
Further, the provision of a single common drive shaft has the advantage that drive wheels and the like for connecting two drive shafts are not required.